The present invention relates to a new floating boom structure.
This boom structure is in particular suitable for defining shipping zones or water areas which may be used for aquatic activities, for example, as swimming areas or for "aquaculture".
A very important application of the invention is for fighting against water pollution caused by floating solid wastes or by chemical products, more particularly hydrocarbon spills.
The boom according to the invention may be used as a stationary boom stretched between two mooring points or as a net or trawl secured at its ends to one or more tug boats, in order to clean a polluted water area.
One presently used prior art boom type comprises those having a cylindrical buoyant member to which a skirt weighted at its lower part is secured, such as the booms described in French Patent No. 2,241,203 and in the publication Offshore, vol. 32, No. 6, June 5, 1972, pages 69-70, Tulsa, U.S.A. A second type of boom, described in French Patent No. 1 305 469, comprises a series of hingedly interconnected floating plates. A third boom type, described in the first addition No. 77 350 to French Patent No. 1 249 315 and in U.S. Pat. No. 4,016,726 comprises a flexible structure forming a barrier provided with transverse stiffeners to which are secured floats adapted to support the structure in a substantially upright position in water, so as to form a screen thereon.
This latter boom type offers, with respect to the former type, the advantage of having a substantially constant height above the water level, which facilitates containment of the polluting agents.
However, the stability of such booms with respect to winds, waves and water currents cannot be sufficiently ensured by the mere weighting of the flexible structure.
This stability can be improved, as described in French Patent No. 2 161 242, by locating the floats on one side or on both sides of the barrier at a distance therefrom as illustrated in French Patent No. 987 479, so-obtained stability being greater as the distance is increased.
A problem arising in a boom of this type is that the float groups distributed along the flexible structure forming the barrier must be maintained at a distance from each other by connecting means of sufficient flexibility to accomodate the swell movements, so that the boom can be deformed with the rolling, pitching, and yawing movements while keeping a substantially constant height above the water level as the boom is being hauled in a line and when it is in its working position, streched between two mooring points or tugged by one or several ships.